Apparatus for collecting dust



Oct 3 1933.

APPARATUS FOR ,COLLECTING DUST 5 Sheets-Sheet 1 Filed Aug. 7, 1931 A 2 I I 1 4 21 f Oct. 3, 1933.

R. F." OMARA 1,928,702

APPARATUS FOR COLLECTING DUST Filed Aug. 7-, 1931 3 Sheets-Sheet 2 Oct. 3, 1933. I QMARA I 1,928,702

APPARATUS FOR COLLECTING DUST Filed Aug. 7. 1931 3 Sheets-Sheet '3 a Inl anfar Patented Oct. 3, 1933 PATENT OFFICE APPARATUS FOR COLLECTING DUST Richard F. OMara, to The Raymond La Fayette, Ind., assignor Brothers Impact Pulverizer Company, Chicago, 111., a corporation of Illinois Application August 7, 1931. Serial No. 555,783

1 Claims. (01.183-34) 4 This invention relates to a certain new and improved apparatus for collecting dust, and more particularly to new and useful improvements in an apparatus for recovering and collecting any 5 solid finely divided material that is carried in suspension in a stream of air or other gases.

- The usual process for recovering dust consists in passing the air stream through a separator,

often of the cyclone type, wherein the greater portion of the suspended material is deposited and collected. A small proportion of very finely divided material will still be suspended in the airstream flowing from the separator. It has been proposed to pass this air-stream through a con- 16 centrator wherein the suspended material is concentrated in a relatively small portion of the airstream, the dust-free air being vented from the concentrator and the dust-laden air returned to the original air-stream. 5

According to the present invention the'original stream of dust-laden air is passed through a concentrator, or preferably a plurality of concentrators arranged in multiple, wherein the suspended material is concentrated in a relatively small portion of the air, and from which the remainder of the air, substantially free from suspended material, is vented. The materialladen air is conducted from the concentrators into a single cyclone separator wherein the major portion of the material is deposited and collected. Preferably the air stream from the separator, which will still contain a certain small quantity of finely divided material, is returned to the original air stream to again pass through the process.

The general object of this invention is to .provide an improved apparatus of the type briefly described hereinabove-and disclosed more in detail in the specifications which follow.

Another object is to provide a new and improved apparatus for separating and collecting suspended dust from the air stream in which it is carried.

Other objects and advantages of the invention will be more apparent from the following detailed disclosure of an approved example of apparatus suitable for carrying out the principles of the invention.

In the accompanying. drawings:

Fig. 1 is a side elevation of the assembled apparatus.

2 is a plan view, on a larger scale and part ally broken away, of the apparatus shown in Fig. 1.

Fig. 3 is an elevation, partially in central vertical section, of one of the improved concentrators.

Fig. 4 is a plan view of the concentrator.

Fig. 5 is an enlarged horizontal section taken substantially on the line 55 of Fig. 3.

Fig. 6 is a horizontal section through the upper portion of the separator, showing a modification.

The apparatus comprises, in general, a main supply conduit A, a battery of similar concentrators B B, B and B, a main air venting conduit C, a fan or blower D for maintaining the air circulation through the concentrators, a cyclone separator E, a return air conduit F and a blower G in the conduit F.

The main supply conduit A splits into a central branch conduit 1 and a pair of side branch conduits 2 and 3 which lead respectively to the concentrators,l3 and B In turn the conduit 1 splits into a pair of similar branch conduits 4 and 5 leading to the respective concentrators B and B 'It will be noted that the branch conduits 2, 3, 4 and 5 are all of equal size, that conduit 1 is equal in cross-section to the sum of conduits 4 and 5, and that main conduit A has a cross-sectional area equal to the sum of conduits 1, 2 and 3, so that the air stream supplied through the main conduit will be divided substantially equally between the several concentrators.

, The several concentrators B B B and B (of which the system may comprise one or more, as will be hereinafter apparent) are all substantially alike with the exception that concentrators B and B in the example here shown, are so designed that the materials therein whirl in a clock-wise direction (Fig. 2) whereas the whirl is in a counter-clockwise direction in concentrators B and B This improved type of concentrator is disclosed more in detail in Figs. 3,4 and 5 and has previously been disclosed and claimed in my copending application Serial No. 555,762, filed August 7, 1931. This concentrator is of a modified cyclone separator type and comprises a closed housing having a central portion 6 of invertedconical form, a large upper substantially cylindrical portion 8 and a small lower substantially cylindrical discharge housing 9. The inlet conduit 2 (of coilcentrator B here shown by way 'of example), leads substantially tangentially. into the larger upper portion 8 of the housing so that a whirling 10 motion will be imparted to the air content of the concentrator, as is well understood in this art. The outlet pipe 10, through which the greater portion of the air is vented, leads through the central portion of the top or closure 11 of the 110 housing and is provided with an extension 12, having an open lower end, leading downwardly A within the concentrator below the inlet passage 2.

A swinging valve or damper 13 is pivoted on a vertical axis 14 within inlet conduit 2 adjacent its discharge end 15 so as to swing toward or from the outer tangential wall of this conduit and thus vary the effective size of the inlet to the concentrator. The eiliciency of the concentrator is a function of the inlet velocity of the air-stream and the fineness and character of the dust to be separated from the air, and it will be apparent that the inlet velocity can be effectively regulated by properly positioning the inlet valve 13. It will be noted that in any position of adjustment of this vertical valve or damper the entering air stream will be directed tangentially along the inner surface of the outer wall of the concentrator so that the maximum whirling or centrifugal effeet will be imparted to the suspended material introduced into the concentrator. The valve or damper may be adjusted in any suitable manner from the outside of inlet conduit 2, as for example by means of the adjusting mechanism indicated generally at 16 in Figs. 3 and 4.

As is usual in a separating apparatus of this type, the suspended material will be deposited against the inner walls of the housing or concentrated in the air adjacent these walls, due to the centrifugal force imparted to the material by the whirling air. and the material will tend to settle by gravity to the lower end of the concentrator. However, unless a positive down draft is provided to carry out this material, too large a proportion of the finely divided material will be caught in the central air vortex and sucked up' through the outlet conduit 10. To prevent this the smaller lower end of the conical housing is provided with the cylindrical extension 9 having the upwardly projecting conical bottom 17, and provided with the outlet 18 leading tangentially from one side of the housing in the direction in which the whirling materials are traveling. A relatively small proportion of the air stream entering the housing through inlet 15 is drawn out through outlet 18, thus producing a sufiicient down draft adjacent the inner walls of the concentrator to effectively suck down the air adjacent these walls which carries the concentrated suspended material. This air, still moving with a whirling motion, will pass out through tangential outlet 18 carrying with it practically all of the suspended material. The upwardly projecting conical member 1*! serves to puncture the central air vortex tending to suck material upwardly through outlet 12, thus maintaining the whirling movement of the air within the lower extension 9 and reducing the upward flow of suspended material to a minimum. If desired, a second conical member 19 may be centrally supported within the lower portion of conical housing 6, as by means of brackets 20 so as to further insure the breaking up of the inner vortex in the lower portion of the concentrator, but ordinarily this additional conical member will not be necessary. The air stream passing out through outlet 12 and conduit 10 will be substantially free from dust or other suspended material.

The outlet conduit 10, and similar air conduits 21, 22 and 23 leading respectively from concentrators B B and B join together to form the main air discharge conduit C, in a portion of which is positioned the main fan or blower D which maintains the necessary air circulation in the concentrating system. This blower D might alternatively be located in the supply conduit A or in some other portion of the circulating system. The dust-free air can be vented from conduit C to the outer air, or may be returned to a circulating system for further use thereof.

The outlets 18 of the several concentrators are connected by similar conduits 24 with the inlet end of the cyclone separator E which may be of usual and well known construction. The several conduits 24 all enter substantially tangentialmaterial will be thrown out centriiugally and will settle out to be collected through spout or conduit 25. The air is drawn out through the conduit F leading from the central upper portion of the separator, an auxiliary fan or blower G preterabl y being positioned in this conduit to positively insure the desired suction through the air outlet conduit F. A small amount of finely divided material will be carried out in the air through conduit F and to prevent loss of this material it is desirable to direct the air from conduit F" back into the main inlet or supply-conduit A, as indicated at 26, so that this relatively small air stream is again passed through the system to deposit its suspended materials.

Instead of the dry separation process above described, a wet separation process could be used,

,as indicated in Fig. 6. Suitable liquid sprays 2'1 are positioned in the discharge ends of conduits 24 so as to wash out the solid materials in the air and carry these materials away in solution or in suspension in the liquid through conduit 25. If the separation is sufliciently complete the air from the separator E need not be returned to conduit A but may be vented directly or into main air discharge conduit C.

In'the general operation or this system the dust-laden air drawn in through conduit A by the suction of fan or blower D (and perhaps by other propulsion. means in the air-circulation system), is divided among the several separators B wherein the suspended material is concentrated in a.

and collected by fan D and vented through conduit C. The relatively small remaining volume oi! air carries the suspended dust into separator E, wherein the major part of thermal; is deposited and separated out through discharge conduit 25,

either dry or in a liquid stream. The small air.

flow through separator E is withdrawn by fan or blower G through conduit F and retumed into the main supply conduit A so that any finely divided materials that may be sucked out in this air stream are not lost but are again passed through the separation process.

the system here disclosed by way of example, one

4 While tour concentrators B have been used in or more concentrators may be used depending on divided solid material that may be carried in suspension in a stream of air or other gases. Also, the term air is used in a general sense to indicate any suitable gas or gases in which the solid material may be carried in suspension.

I claim:

1. A dust-collecting apparatus comprising a. plurality of similar concentrators, means including a main conduit and a plurality of branch conduits leading therefrom for conducting the dust-laden air into the several concentrators, means for venting the dust-free air from each concentrator, a separator, a plurality of conduits leading from the several concentrators into the separator through which the concentrated dust is conveyed in suspension in a relatively small portion of the original air stream, means for collecting the major portion of the dust from the separator, and means for returning the air from the separator to the main conduit.

2. A dust-collecting apparatus comprising a concentrator including a housing of inverted conical form, a conduit for dust-laden air extending tangentially into the upper portion of the housing, a valve at the inlet to the concentrator for regulating the velocity of the air stream projected into the concentrator, an outlet for dustfree air leading from the central upper portion of the housing, an outlet conduit leading tangentially from the smaller end of the housing through which the dust is carried in suspension in a relatively small portion of the original air stream,

a cyclone separator into the upper portion of which the last mentioned conduit leads tangen tially, a conduit leading from the upper central portion of the separator for conducting the air therefrom back into the first-mentioned conduit, and blowing means for causing the air-streams to circulate through the concentrator and separator.

3. A dust-collecting apparatus comprising a plurality of similar concentrators each including a housing of inverted conical term, a main conduit for dust-laden air, a plurality of branch conduits leading from the main conduit and each leading tangentially into the upper portion of one of the concentrator housings, an outlet conduit for dust-free air leading from the upper central portion of each housing, an outlet conduit leading tangentially from the smaller lower end of each housing, a cyclone separator, the several outlet conduits all leading tangentially into the upper portion or the separator, an air outlet conduit leading from the uppercentral portion of the separator back into the main conduit, and a blower in the'last mentioned outlet conduit. 4

4. A dust-collecting apparatus comprising a plurality of similar concentrators each including a housing of inverted conical form, a main conduit for dust-laden air, a plurality of branch conduits leading from the main conduit and each leading tangentially into the upper portion of one ofthe concentrator'housings, an outlet conduit for dust-free air leading from the upper central portion of each housing, an outlet conduit leading-tangentially from the smaller lower end of each housing, a cyclone separator, the several outlet conduits all leading tangentially into the upper portion of the separator, an air outlet conduit leading from the upper central portion of the separator back into the main conduit, and blower means for causing circulation of the air streams through the concentrators and separators.

5. A dust-collecting apparatus comprising a plurality of similar concentrators each including a housing of inverted conical form, a main conduit for dust-laden air, a plurality of branch conduits leading from the main conduit and. each leading tangentially into the upper portion of one of the concentrator housings,- an outlet conduit for dust-free air leading from the upper central portion of each housing, a main air venting conduit into which the several outlet conduits leads, a blower in this venting conduit for causing the air circulation through the concentrators,

an outlet conduit leading tangentially from the smaller lower end of each housing, a cyclone separator, the several outlet conduits all leading tangentially into theupper portion of the separator, an air outlet conduit leading from the upper central portion of the separator back into the main conduit, and a blower in the last mentioned outlet conduit.

6. A dust-collecting apparatus comprising a plurality of similar concentrators each including a housing of inverted conical form, a main conduit for dust-laden air, a plurality of branch conduits leading from the main conduit and each leading tangentially into the upper portion of one of the concentrator housings, a valve at the inlet to each concentrator for regulating the velocity of the air projected into the concentrator, an

outlet conduit for dust-free air leading from the upper central portion of each housing, an outlet conduit leading tangentially from the smallerlower end of each housing, a cyclone sep-- arator, the several outlet conduits all leading tangentially into the upper portion of the separator, an air outlet conduit leading from the upper central portion of the separator back into the main conduit, and blower means for causing circulation of the air streams through the concentrators and separator.

7.-A dust-collecting apparatus comprising a plurality of similar concentrators each including a housing of inverted conical form, a main conduit for dust-laden air, a plurality of branch conduits leading from the main conduit and each leading tangentially into the upper portion of one of the concentrator housings, an outlet conduit for dust-free air leading from the upper central portion of each housing, an outlet conduit leading tangentially from the smaller lower end of each housing, a cyclone separator, the several outlet conduits all leading tangentially into the upper portion of'the separator, means for spraying a liquid into the air-streams adjacent the discharge end'of each of these outlet conduits, means for collecting the liquid and dust carried thereby, and means for venting the air from the separator.

RICHARD F. OMARA. 

